The present invention relates to electrical switches, primarily of the type known as limit switches. Such limit switches commonly utilize a spring-loaded plunger, whose end bears against a lever arm mounted on a fulcrum.
According to the best information of applicant, prior art limit switches operate by deflection of the lever arm in a single direction. If the purpose of the user is to sense deflection in two opposite directions, for example, to sense both high and low limits, two separate switches would be required.
It has been suggested in the prior art that the positioning of the lever and fulcrum by which a limit switch is operated may be varied so that, with the fulcrum on one side of the plunger, the operating arm will depress the plunger if deflected in one direction, whereas if the fulcrum be positioned on the opposite side of the plunger, the switch may be actuated by deflection of the operating arm in the opposite sense. Such a construction is shown in U.S. Pat. No. 2,547,765 to Lund.